Using the Coaxial Probe Method for permittivity measurements of liquids at high temperatures

The use of the Coaxial Probe Method for dielectric characterization of liquid materials and the cares that should be taken to make reliable permittivity measurements at high temperatures are described in this work. Due to the lack of a standard procedure in the literature for these measurements, the validation of the method involved the characterization of different liquids of known properties (water and alcohols) at different frequencies and temperatures. An experimental procedure was developed according to manufacturer's recommendations and our own experience in the lab. The reliability of the technique was evaluated by comparing the deviation of the measured results from material data in the literature with the accuracy limits supplied by the manufacturer of the probe. © 2009 SBMO/SBMag.